PATIENT POSITION DURING ANESTHESIA - Nurse …

1 PATIENT POSITION DURING ANESTHESIA By David Roy Godden CRNA, MSN LECTURE OBJECTIVES Gain an understanding of safe positioning basics State the correct hand and arm positioning for supine, lateral decubitus and prone positions. Be able to recite the potential nerve injuries of each PATIENT POSITION . Identify the complications of the sitting POSITION . OBJECTIVES CON T Define and understand the hemodynamics of each PATIENT POSITION . Understand and be able to verbalize the respiratory responses of differing PATIENT positions while awake and under general ANESTHESIA . Understand the process and risks of Field Avoidance the turned PATIENT . Discuss Post Operative Visual Loss (POVL) Case Study: Complications of Prone POSITION LOOK FOR KEY POINTS Positioning is often a compromise between what is required for surgical exposure and PATIENT comfort!

2 Do not place sedated or anesthetized patients in positions that they are not comfortable with when awake. If in doubt about patients safety have the PATIENT assume the POSITION on the OR table before induction to see how they tolerate the POSITION . PATIENT positioning is the joint responsibility of OR Nursing, ANESTHESIA and Surgery. All three individuals and groups that represent them will be held liable if errors in positioning cause PATIENT harm. Document! DOCUMENTATION OF POSITIONING The only thing that represents what was done in the operating room in a court of law is your testimony and your documentation. How much do you think you can remember from one case to the next and how much of your story will the court officers believe without your careful documentation in the ANESTHESIA record?

3 What to document? Pre-operative PATIENT limitations in movement strength and nerve abnormalities. Does the PATIENT have numbness tingling or loss of sensation to any extremity pre-operatively? Does the PATIENT have foot drop? MASK INJURIES Potential for corneal abrasion is always present when mask ventilating patients . Keep hanging badges away from the patients face when hand ventilating (don t use the term "Bagging the pt ). Always remember the ABC s. Where does E come in the ABC lineup? When do you tape the eyes closed knowing all of the above. A controversial question. MASKING INJURIES Face straps which are tight across the patients face with prolonged use may cause injury to the facial nerve.

4 What are the five branches of the facial nerve remembering the mnemonic, Two zebras bit my cat The bucal branch is most likely injured with a face strap compression. Temporal Zygomatic Bucal Mandibular cervical DORSAL DECUBITUS POSITIONS Humans, giraffes and dinosaurs share one thing in common. What is it? Gravity effects blood flow and much of pulmonary mechanics. In the supine POSITION gravity equalizes blood pressure gradients between heart and arteries in the head and lower extremities CORRECT ANATOMICAL POSITION What is the ventral surface? What is the dorsal surface Note: Dorsal to dorsal and ventral to ventral HAND POSITIONING Lying at attention requires correct arm and hand POSITION to minimize the chances of nerve injuries.

5 Arms are to be less than 90 degrees lateralized from the thorax in correct anatomical POSITION looking at the shoulders. This will minimize the chance of brachial plexus injury. HAND POSITIONING Arms at side of body must be in correct dorsal to dorsal alignment with the arms supinated OR palms toward the body is OK as well. The ulnar nerve passes close to the surface of the skin in the medial condyle of the elbow. The olectranon will protect the nerve if placed downwards. Radial nerve injury is possible with ether screen compression to the lateral arm. Radial nerve injury may result in wrist drop. WHAT IS SUPINATION Correct anatomical POSITION is lying at attention Palms are ventral surface so ventral to ventral Dorsal to dorsal mean back of hands to down in the supine POSITION .

6 DORSAL DECUBITUS POSITIONS Head tilt either upwards or downwards will change the pressure gradients. A movement of cm in vertical elevation will change the blood pressure 2 mm Hg. In the parturient an IV bag under the right hip will shift the gravid uterus to the left. Have you heard of Aorto-caval syndrome? HEAD DOWN THINGS Lowering the head will increase the pressure in the cerebral veins which may lead to vascular head ache, congestion of nasal mucosa and conjunctiva in healthy individuals. This may lead to edema in the larynx as well. The sclera is the window to the vocal cords! Head lowering in patients with intra-cranial lesions will exacerbate the condition raising CPP and ICP (what's the formula for this?)

7 AUTONOMIC FUNCTION Aortic arch and carotid sinus house barorecetors that are part of the bodies homeostatic mechanism to maintain blood pressure within a narrow range. Increased firing of the receptors when stretched from an increase in blood pressure is part of a negative feed back loop. The increased firing from the baroreceptors enhances the parasympathetic nervous system lowering blood pressure and slowing the heart rate. Remember this! What are the afferent and efferent nerves responsible for the baroreceptor reflexes? AUTONOMIC NERVOUS SYSTEM The carotid sinus baroreceptors are innervated by the sinus nerve of Hering part of glossopharyngeal nerve. The glossopharyngeal nerve synapses in the nucleus tractus solitarius Aortic arch is innervated by Vagus.

8 Stimulation of the NTS causes firing of efferent Vagus. RESPIRATORY EFFECTS AWAKE VS ANESTHETIZED PATIENT Is there a difference in the respiratory effects between an awake and anesthetized pt? Awake pt s maintain V/Q matching whether standing, lying down or side lying. In an anesthetized paralyzed pt V/Q matching is not maintained. Why? RESPIRATORY EFFECTS Respiratory mechanics will suffer in the head down POSITION how? Review West s zones of the lung. Zone 1 PA>Pa>Pv Zone 2 Pa>PA>Pv Zone 3 Pa>Pv>PA TRENDELENBURG RESPIRATORY ISSUES Normal excursion of the diaphragm in head down POSITION is impeded and increase the work of breathing. In the paralyzed mechanically ventilated PATIENT , higher peak pressures will be required for adequate ventilation.

9 RESPIRATORY THINGS YOU NTK Supine patients develop VQ mismatch due to vascular congestion in the dorsal portions of the lung and changes in compliance. The dorsal lung (now zone 3) will have reduced compliance. Passive ventilation tends to distribute gas preferentially to the more easily distensible substernal units where pulmonary blood flow volume is less (Barish, 2006). MORE RESPIRATORY THINGS To prevent development of significant V-Q imbalance DURING use of controlled ventilation, tidal volumes must be used that are greater than the average amount that is sufficient for the spontaneously breathing conscious pt. Compare and contrast the awake spontaneously breathing pt and the paralyzed mechanically ventilated pt in the lateral POSITION .

10 OH NO MR. BILL HIGH PEAK PRESSURE How would you attempt to decrease Peak pressures DURING mechanical ventilation in the paralyzed anesthetized PATIENT ? Hint: deepen anesthetic, muscle relaxation, decrease Vt and increase Rate, change I:E ratio from 1:2 to 1 Consider Pressure Control ventilation due to its decelerating waveform. AIRWAY ISSUES WITH HEAD DOWN Which way will an intubated patients ETT migrate when placed in Trendelenburg POSITION ? Does the Peak airway pressure increase when the PATIENT is positioned head down? By how much. Recheck breath sounds after a POSITION change especially if peak airway pressures change. Right main stem intubation can be an issue when placing the PATIENT in steep Trendelenburg POSITION .